We have a popular topic in our community - "Known Issues". We set it as a collection type topic and we wish to create sub-topics under it - for example, for specific modules in our product, like "Calendar". Now, members use the "Calendar" topic for other types of content, not only for "Known Issues". When a member enters the "Known Issues" topic, and wish to filter the content by selecting a sub-topic, the content displayed is not filtered under "Known Issues" >> "Calendar", but shows the member all of the content that was tagged with the "Calendar" topic. How can I configure topic and sub-topics to create this type of hierarchy and filtering?